1999 CE (most likely)
The Black Mother became famous for her perception and understanding of all layers of reality, and was a renowned prophetess. The stories say that she could sense the deepest inner thoughts of an individual from hundreds of leagues away, and kept a list of sinners and saints among her peers.
After she abandoned Zapathasura and his war, her sire ordered her name stricken from all records – therefore she is often confused with Kali Ma, the Hindu goddess of death, destruction, and the end of the world.
She was prepared for the coming of Alexander the Great and Embraced one of his soldiers, Phaedyme. She accompanied her childe and traveled Europe for centuries, finally establishing herself in southern Gaul.
There is no indication that a creature as powerful as Black Mother was destroyed before the Final Nights. If she did survive, she certainly met her end during the Week of Nightmares, either consumed by her newly awakened progenitor or killed during the madness caused by its Final Death.